#include "bilbao/util/Base64.h"

namespace bilbao
{
	namespace util
	{
		const String Base64::CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
			"abcdefghijklmnopqrstuvwxyz"
			"0123456789+/";

		Base64::Base64( void )
		{

		}

		Base64::~Base64( void )
		{

		}

		static inline bool is_base64(unsigned char c)
		{
			return (isalnum(c) || (c == '+') || (c == '/'));
		}

		String Base64::encode( const String& data )
		{
			const BYTE* _data = reinterpret_cast<const BYTE*> (data.c_str());
			return encode( _data, data.length() );
		}

		String Base64::encode( const BYTE* data, UINT32 in_len )
		{
			String ret;

			int i = 0;
			int j = 0;
			BYTE char_array_3[3];
			BYTE char_array_4[4];

			while ( in_len-- )
			{
				char_array_3[i++] = *(data++);
				if (i == 3)
				{
					char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
					char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
					char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
					char_array_4[3] = char_array_3[2] & 0x3f;

					for (i = 0; (i < 4); i++)
						ret += CHARS[char_array_4[i]];
					i = 0;
				}
			}

			if (i)
			{
				for (j = i; j < 3; j++)
					char_array_3[j] = '\0';

				char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
				char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
				char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
				char_array_4[3] = char_array_3[2] & 0x3f;

				for (j = 0; (j < i + 1); j++)
					ret += CHARS[char_array_4[j]];

				while ((i++ < 3))
					ret += '=';

			}

			return ret;

		}

		String Base64::decode( const String& data )
		{
			int in_len = data.size();
			int i = 0;
			int j = 0;
			int in_ = 0;
			BYTE char_array_4[4], char_array_3[3];
			String ret;

			while (in_len-- && (data[in_] != '=') && is_base64(data[in_]))
			{
				char_array_4[i++] = data[in_];
				in_++;
				if (i == 4)
				{
					for (i = 0; i < 4; i++)
						char_array_4[i] = CHARS.find(char_array_4[i]);

					char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
					char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
					char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

					for (i = 0; (i < 3); i++)
						ret += char_array_3[i];
					i = 0;
				}
			}

			if (i)
			{
				for (j = i; j < 4; j++)
					char_array_4[j] = 0;

				for (j = 0; j < 4; j++)
					char_array_4[j] = CHARS.find(char_array_4[j]);

				char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
				char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
				char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

				for (j = 0; (j < i - 1); j++)
					ret += char_array_3[j];
			}

			return ret;
		}
	}
}
